The present invention relates to the delivery of electrical energy to bodily tissues for therapeutic purposes, and more specifically to devices and methods for treating conditions through delivery of electrical energy using a balloon and electrode device.
The use of electrical stimulation for treatment of medical conditions has been well known in the art for nearly two thousand years. It has been recognized that electrical stimulation of the brain and/or the peripheral nervous system and/or direct stimulation of the malfunctioning tissue, which stimulation is generally a wholly reversible and non-destructive treatment, holds significant promise for the treatment of many ailments.
One of the most successful modern applications of the relationship between muscle and nerves is the cardiac pacemaker. Although its roots extend back into the 1800's, it was not until 1950 that the first practical, albeit external and bulky pacemaker was developed. Dr. Rune Elqvist developed the first truly functional, wearable pacemaker in 1957. Shortly thereafter, in 1960, the first fully implanted pacemaker was developed.
Among the developments in the treatment of patients with heart ailments has been the introduction of electrodes for electrical stimulation through the esophagus. For example, esophageal stimulation and monitoring leads are known in the art, adapted specifically for cardiac pacing, as disclosed in U.S. Pat. Nos. 4,574,807; 4,198,936; and 4,706,688, the entire disclosures of which are hereby incorporated by reference herein. Typically, esophageal pacing leads include one or more balloons, adapted to stabilize the location of the lead in the esophagus. In some cases, the electrodes are located on the balloon, as in U.S. Pat. No. 4,198,936. In other cases, the electrodes are located proximal or distal to the balloon as in U.S. Pat. No. 4,574,807. In some other cases, the balloon is arranged eccentrically, and is used both to stabilize the lead and urge the electrodes into contact with the anterior inner surface of the esophagus, as in U.S. Pat. No. 4,706,688.
More specifically, U.S. Pat. No. 4,706,688 discloses a device 10 inserted into the esophagus 34 of a patient. The device 10 is inserted through the nasal region 32, through the esophagus 34 and into the stomach 36. Once the device 10 has been inserted, fluid is caused to flow along airway 24 such that a balloon cuff 18 expands. The purpose of cuff 18 is to locate the gastroesophageal junction just proximate to the cuff 18. A second balloon cuff 20 is located posterior to the heart region 40 such that when it is expanded, at least some of the electrodes 26 abut against the esophagus 34 adjacent the heart 40.
U.S. Pat. No. 5,056,532 discloses a lead having an elongated flexible lead body 10, which is provided with three longitudinal lumens. At the distal end of the lead a balloon 12 is mounted around the external surface of the lead body 10. Proximal to balloon 12 is a second balloon 20. An electrode lead 24 is slideably mounted within a lumen within lead body 10, and ventricular electrodes 26 and 28 are mounted to lead 24. The electrode lead 24 and electrodes 26 and 28 may be slideably adjusted relative to the position of balloon 20. A third balloon 30 is located proximal to balloon 20. Atrial electrodes 34 and 36 are located on electrode lead 24, such that movement of lead 24 within the lead body 10 adjusts the positions of electrodes 34 and 36 relative to balloon 30.
The lead is advanced through the mouth or the nasal cavity, down the esophagus until the distal end 18 of the lead is well within the stomach. The balloon 12 is then inflated, and the lead is withdrawn until balloon 12 lies against the gastroesophageal junction. Balloons 20 and 30 are then inflated, urging electrode lead 24 against the anterior inner surface of the esophagus, closest to the heart. Notably, when the balloons 20 and 30 are inflated, electrodes 26 and 28 and electrodes 34 and 36 are urged into contact with the anterior inner surface of the esophagus.
It has been discovered that the above esophageal electrode and balloon configurations are not satisfactory for all applications. Accordingly, there is a need in the art for new products and methods for treating conditions through delivery of electromagnetic impulses using balloon electrodes.